Tier 2 platforms

Tier 2 platforms work (to varying degrees), but we rely on community support for
developing, testing, and building distributions. We may release GHC
with some Tier 2 platforms not working.

Platform-specific bugs on Tier 2 platforms are marked "low priority" (unless there's
a strong reason not to do so), not because they are unimportant to the users of that
platform, but to express the fact that they aren't going to hold up the release.

We'd like to promote as many
Tier 2 platforms as possible to Tier 1, as soon as they meet the Tier 1 criteria.

*S1 Goetz Isenmann ​reports that GHCi is currently unable to load compiled code that refers to errno.*S2 but see #591

In most cases, binaries for the tier 2 platforms can be downloaded from the Distribution Packages page, e.g. you can get binaries for most of the Linux platforms from Debian. In some cases, for example the Solaris platforms, you'll need to go to the download page of a particular release to get a bindist.

Definitions

Reg'd (Registerised)

A catch-all term for a number of optimisations, which collectively
require the mangler (a Perl script that post-processes the
assembly output from gcc). Unregisterised builds require only a
working C compiler and are hence far more portable. The
registerised optimisations include:
direct tail calls (as opposed to using the "mini-interpreter"),
info-tables adjacent to entry code, and virtual machine registers mapped
to real machine registers.

GHCi

The interactive environment, including dynamic linking of object
code and dynamic generation of FFI calls.